Tunnel-type gas burner



May 21, .1929.

w. M. HEPBURN TUNNEL TYPE GAS BURNER Filed Oct. 28, 1927 INVENTOR. NMMHEPBUIZN.

fr ATTORNEY.

Patented May v21, 1929.

UNITED STATES PATENT oFF1cE.

WILLIAM m. museum, or TOLEDO, 01:10, assrcivon '10. THE sumacn counus'rioii comrm, me, or .ronano, 0310, A conrona'rron or NEW Yonx.

TUNNEL-TYPE GAS BURNER,

Application filed October 28, 1927. Serial No. 229,4;28.

This invention relates to improvements in gas. burners and more particularly to gas burners of the type having refractory tunnels within which combustion occurs, an example 5 of this type being shown in patent to Willson 1,289,992.

This invention'has among its objects to increase the usefulness of gas burners of the tunnel type by'providing 'a'bank of burner 1 tiles which will automatically adjust itself to differences in expansion and contraction; to make the individual sections of the burner bank of such form that theymay be easily nested to present a compact burner surface, 1 and in general to reduce the cost of manufacture and upkeep of tunnel type burners and to increase the efliciency of the burners.

Referring to the drawings wherein the preferred form of burner is shown, Fig. 1 is in part an elevational and in part a sec ional view ofthe improved burner; Fig. 2 is a plan view of a suflicient portion of the burner surface to illustrate the nature of the invention,

and Fig. 3 is a perspective view of one of the elements of the burner construction.

In the drawings, 10 indicates a gaseous mixture supply chamber to which is connected at any suitab e point a gaseous mixture sup ly pipe 12. The upper side of the cham r so serves as a base late 14 for supportin a multiplicity of tubular refractory coin ustion tunnels in a manner hereinafter specified.

On the upper side ofthe base plate 14 are formed a series of'cylindricalobosses 16 each of which is provided with an aperture 18. These apertures constitute spuds or nozzles through which the explosive mixturepasses from the sup 1 chamber for burning. Cente'red on each is a tubular combustion 40 tunnel or tile 20 of larger internal diameter than the diameter of said apertures 18.

The combustion tunnels are made from refractory material and are preferably hexagonal in cross section. The hexagonal form is referred because it allows the greatest numr of tunnels per unit area withuniform spacing between the tunnels. In accordance with this invention the tunnels are supported 7 "on the base plate 14 out of individual contact with each other or, to put the matter in another way, the tunnels are. loosely nested. By-

loosely nesting the tunnels, expansion and contraction may occur without destructive stresses being set up such as would occur if a plurality of tunnels were formed in a solid refractor body. Another important result attained y making the combustion tunnels as f individual, members and, supporting them in loosel nested position is that in case of breakage 0 a tunnel from one cause or another, replacement can be made by merely lifting out the damaged tunnel and replacing it by a new one. It'will now be seen that by making the tunnels as individual members-I accomplish a number of important results without in any manner detracting from the efliciency of the" 7 burner, that is to say, by making the tunnels as individual units and by nesting them loose-- ly the liability of breakage of the tunnels un'- der expansionand contraction of the burner surface as a whole is completely eliminated and in caseof breakage of a tunnel from one causeor-another, replacement by a new tunnel is only a matter of lifting out the damaged tunnel and inserting a new one. Other advantages from a manufacturing standpoint will be readily apparent to those skilled in the art. For example in making burners of different sizes, aside from prov1dingthe proper size of burner base plate, it is only a matter of using the requisite number of tunnels from a stock supply.

By providing a relatively great number of relatively-small capacity combustion tunnels instead of fewer tunnels of large capacity where explosive gaseous mixtures are to be .burned, a very desirable degree of flexibility of operation of the burner maybe had without danger of back flash into the supply cham r. v The ratio between the length of the tunnel and the internaldiameter thereof is an im ortantfactor in the successful 0 ration o the burner. I have found that t e best results a are obtained where the ratio between the length and diameter of the tunnel are as four is to one. Thus for a tunnel of on half inch diameter the length of the tunnefshoul-d be about two inches. Considerable variation may be made from-theselrelative sizes but taking into consideration all the various factors said ratio is the mostdesirable.

What is claimed is: v tunnels being arranged one in axial alinement In a gas burner for burning a preformed with each feed ort and out of lateral conmixture of gas and air, the combination of tact with each 0t er, the walls of said tunnels 10 a mixture supply chamber having a flat wall being relatively thick.

5 which is provided with a plurality of feed In testimony whereofl aifix my signature.

orts' therethrough, a bed of refractory com- 7 ustion tunnels abutting on said wall, the WILLIAM HEPBURN. 

